The present invention relates generally to a system for viewing an image generated by an electron microscope. More particularly, the invention is concerned with an electron-microscopic image viewing system for a transmission electron microscope in which an image of a specimen or sample as generated by a transmission electron microscope and a corresponding image generated through simulation (referred to as the simulated image) can be concurrently displayed on a same or separate cathode ray tube (CRT) displays.
In recent years, electron microscope of a structure equipped with a television (TV) camera for allowing the electron-microscopic image to be viewed or examined on a CRT monitor as well as similar (transmission) electron microscope having expanded functions and applicabilities are manufactured on the commercial basis, as is reported in "Proceedings of the 43rd Annual Meeting of the Electron Microscopy Society of America", 1985, pp. 140-141, and "Proc. XI-th Cong. on Electron Microscopy in Kyoto", 1980, pp. 453-454.
However, the prior art electron microscope systems mentioned above are equipped with only the function of displaying and storing the image to be viewed.
In an electron microscope having an increased magnification of 20,000 to 30,000 so that a specimen or sample can be observed at the level of atom, such situation is often encountered in which an image being viewed presents utterly different appearance even when the conditions for observation are changed only a bit, e.g., with deviation of the focal point only a few hundred angstroms (.ANG.). Further, in an electron diffractograph, diffraction intensity as well as diffraction pattern may undergo remarkable changes even with only a bit of change in the viewing conditions for observation.
Under the circumstances, interpretation of the electron-microscopic image (e.g. determination of atomic array, electron diffraction pattern and others) encounters a great difficulty.
To cope with the problem mentioned above, it has been practiced in the art to photograph an electronmicroscopic image under given viewing conditions while performing simulation on the same condition, wherein the electron-microscopic image or the like is interpreted or analyzed by comparing it with the simulated image (i.e. image obtained through simulation).
However, in the prior art systems, simulation of the electron-microscopic image or the like has been performed independent of observation and/or recording of the actual electron-microscopic image, involving thus troublesome and time consuming procedure in setting the conditions for simulation. In that case, the image will be simulated under the conditions differing from those set for the actual viewing or observation.